RATIONALE: Adaptive Multiple Features Method (AMFM) lung texture analysis software recognizes high-resolution computed tomography (HRCT) patterns.
OBJECTIVES: We evaluated AMFM and visual quantification of HRCT patterns and their relationship with disease progression in Idiopathic Pulmonary Fibrosis.
METHODS: IPF patients in a clinical trial of prednisone, azathioprine, and N-acetylcysteine underwent HRCT at study start and finish. Proportion of lung occupied by ground glass, ground glass-reticular (GGR), honeycombing, emphysema, and normal were measured by AMFM and 3 radiologists, documenting baseline disease extent and post-baseline change. Disease progression includes composite mortality, hospitalization, and 10% FVC decline.
MEASUREMENTS AND MAIN RESULTS: Agreement between visual and AMFM measurements was moderate for GGR (Pearson's correlation r=0.60 p<0.0001 and mean difference -0.03 with 95% limits of agreement -0.19,0.14). Baseline extent of GGR was independently associated with disease progression when adjusting for baseline Gender-Age-Physiology stage and smoking status (HR per 10% visual GGR increase 1.98 CI95% 1.20,3.28 p=0.008 and HR per 10% AMFM GGR increase 1.36 CI95% 1.01,1.84 p=0.04). Post-baseline visual and AMFM GGR trajectories were correlated with post-baseline forced vital capacity trajectory (r=-0.30 CI95% -0.46,-0.11 p=0.002 and r=-0.25 CI95% -0.42,-0.06 p=0.01, respectively).
CONCLUSIONS: More extensive baseline visual and AMFM fibrosis (as measured by ground glass-reticular densities) is independently associated with elevated hazard for disease progression. Post-baseline change in AMFM- and visually-measured ground glass-reticular densities are modestly correlated with change in forced vital capacity. AMFM measured fibrosis is an automated adjunct to existing prognostic markers, and may allow for study enrichment with subjects at increased disease progression risk.
|Journal||American Journal of Respiratory and Critical Care Medicine|
|Early online date||21 Oct 2016|
|Publication status||Published - 1 Apr 2017|